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1.
Transplant Proc ; 40(2): 590-3, 2008 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-18374137

RESUMEN

Previously, a strategy for monitoring pigs intended for cell transplantation was developed and successfully applied to several representative herds in New Zealand. A better understanding of porcine viruses' epidemiology in New Zealand has been achieved, and, as a result, a designated pathogen-free (DPF) herd has been chosen as a good candidate for xenotransplantation. This herd is free of all infectious agents relevant to xenotransplantation. The presented study of pig endogenous retrovirus (PERV) transmission with cocultures in vitro has shown no evidence of PERV transmission from DPF pig tissue. Additionally, in PERV-C-positive DPF donor pigs tested, a specific locus for PERV-C present in miniature swine possibly associated with the transmission of PERV was absent. The data on PERV transmission allowed classifying the DPF potential donors as "null" or noninfectious pigs.


Asunto(s)
Retrovirus Endógenos/patogenicidad , Infecciones por Retroviridae/transmisión , Organismos Libres de Patógenos Específicos , Enfermedades de los Porcinos/virología , Trasplante Heterólogo , Crianza de Animales Domésticos/normas , Animales , Recuento de Células , Línea Celular , Retrovirus Endógenos/genética , Retrovirus Endógenos/aislamiento & purificación , Feto , Humanos , Riñón/embriología , Riñón/virología , Masculino , Nueva Zelanda , Infecciones por Retroviridae/prevención & control , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Seguridad , Porcinos , Testículo/embriología , Testículo/virología
2.
Cell Transplant ; 17(12): 1381-8, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-19364075

RESUMEN

Previously a strategy for monitoring of pigs intended for cell transplantation was developed and successfully applied to several representative herds in New Zealand. A designated pathogen-free (DPF) herd has been chosen as a good candidate for xenotransplantation. This herd has previously tested free of infectious agents relevant to xenotransplantation and we present here an in depth study of porcine endogenous retrovirus (PERV) transmission. A panel of assays that describes the constraints for the transmission of PERV has been suggested. It includes a) infectivity test in coculture of DPF pig primary cells with both human and pig target cell lines; b) RT activity in supernatant of stimulated primary cells from DPF pigs; c) viral load in donor's blood plasma; d) PERV proviral copy number in DPF pig genome; e) PERV class C prevalence in the herd and its recombination potential. There was no evidence of PERV transmission from DPF pig tissue to either pig or human cells. Additionally, there was no evidence of PERV RNA present in pig blood plasma. PERV copy number differs in individual pigs from as low as 3 copies to 30 copies and the presence of PERV-C varied between animals and breeds. In all DPF pigs tested, a specific locus for PERV-C potentially associated with the recombination of PERV in miniature swine was absent. Presented data on the PERV transmission allows us to classify the DPF potential donors as "null" or noninfectious pigs.


Asunto(s)
Retrovirus Endógenos/patogenicidad , Infecciones por Retroviridae/veterinaria , Enfermedades de los Porcinos/virología , Animales , Línea Celular , Cartilla de ADN , Retrovirus Endógenos/enzimología , Retrovirus Endógenos/genética , Humanos , Riñón , Nueva Zelanda , Reacción en Cadena de la Polimerasa , ADN Polimerasa Dirigida por ARN/genética , ADN Polimerasa Dirigida por ARN/metabolismo , Infecciones por Retroviridae/transmisión , Organismos Libres de Patógenos Específicos , Porcinos/virología , Proteínas Virales/genética
3.
Transplant Proc ; 37(8): 3505-8, 2005 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-16298643

RESUMEN

BACKGROUND: A nonhuman primate model of diabetes is valuable for assessing porcine pancreatic islet transplants that might have clinical benefits in humans. METHODS: Neonatal porcine islets, microencapsulated in alginate-polyornithine-alginate, were injected intraperitoneally (10,000 IEQs/kg islets) into eight adult male cynomolgus monkeys rendered diabetic with streptozotocin. Eight diabetic controls were given an equivalent dose of empty placebo capsules. All subjects received a repeat transplant 3 months after the first. RESULTS: The transplant was well tolerated and no adverse or hypoglycemic events occurred. There were two deaths from nontransplant treatment or diabetic complications unrelated to the transplants. After transplantation, the average insulin dose was reduced in the islet-treated group and increased in the control group. At 12 weeks after the first transplant there was a mean 36% (95% CI: 6% to 65%, P = .02) drop in daily insulin dose compared with the control group. After 24 weeks the difference increased to a mean of 43% (95% CI: 12% to 75%, P = .01) without significant differences in blood glucose values between the two groups. Individual responses after islet transplant varied and one monkey was weaned off insulin by 36 weeks. At terminal autopsy, organs appeared normal and there was no visible peritoneal reaction. No animal had polymerase chain reaction (PCR)-amplified signals of porcine endogenous retrovirus or exogenous virus infections in blood or tissues. CONCLUSION: Repeated intraperitoneal transplantation of microencapsulated neonatal porcine islets is a safe procedure in diabetic primates. It was shown to result in a significant reduction in insulin dose requirement in the majority of animals studied, whereas insulin requirement increased in controls.


Asunto(s)
Alginatos , Diabetes Mellitus Experimental/cirugía , Trasplante de Islotes Pancreáticos/métodos , Trasplante Heterólogo/métodos , Animales , Animales Recién Nacidos , Glucemia/metabolismo , Cápsulas , Diabetes Mellitus Experimental/sangre , Diabetes Mellitus Experimental/tratamiento farmacológico , Modelos Animales de Enfermedad , Ácido Glucurónico , Ácidos Hexurónicos , Insulina/uso terapéutico , Macaca fascicularis , Masculino , Porcinos
4.
Transplant Proc ; 37(1): 466-9, 2005.
Artículo en Inglés | MEDLINE | ID: mdl-15808678

RESUMEN

Neonatal porcine islets within alginate microcapsules transplanted intraperitoneally (IP) or within semi-permeable macrocapsules (TheraCyte) and transplanted subcutaneously (SC) survive and reverse diabetes for up to 16 weeks in diabetic autoimmune nonobese diabetic (NOD) mice. The islets in microcapsules transplanted IP into nondiabetic cynomolgus monkeys survived for 8 weeks. Similar results were shown with islets transplanted in TheraCytes. Neither species showed adverse effects or evidence of infection with porcine endogenous retroviruses or other endemic pig viruses. Proof of principle is illustrated for successful xenotransplantation in humans.


Asunto(s)
Cápsulas , Trasplante de Islotes Pancreáticos/fisiología , Trasplante Heterólogo/fisiología , Animales , Diabetes Mellitus Tipo 1/cirugía , Trasplante de Islotes Pancreáticos/métodos , Trasplante de Islotes Pancreáticos/patología , Macaca fascicularis , Ratones , Ratones Endogámicos NOD , Porcinos , Trasplante Heterólogo/patología
5.
Transplant Proc ; 37(1): 470-1, 2005.
Artículo en Inglés | MEDLINE | ID: mdl-15808679

RESUMEN

The testis has been shown to be a privileged site for transplantation of allogenic islets in rodents, and the testicular cell aggregates are thought to confer this immunologic privilege. Recently, a group in Mexico reported transplantation of cocultured neonatal porcine islets and Sertoli cells resulting in insulin independence in nonimmunosuppressed type 1 diabetes patients. We have transplanted similar islets alone (naked islets) or cocultured islets with Sertoli cells (islet/Sertoli cells) into an omental site and other locations of nonimmunosuppressed, streptozotocin-induced diabetic male Sprague Dawley (SD) rats. Histologic examination showed viable neonatal porcine islets survived in xenografted rodents for at least 2 days, and some glucagon and inhibin stained cells appear to have survived for 4 days posttransplantation. However, histological examination did not demonstrate any difference in xenograft survival in the islets/Sertoli cells mixture compared to naked islets when transplanted into these nonimmunosuppressed diabetic rats.


Asunto(s)
Diabetes Mellitus Experimental/cirugía , Trasplante de Islotes Pancreáticos/patología , Células de Sertoli/trasplante , Trasplante Heterólogo/patología , Animales , Animales Recién Nacidos , Células Cultivadas , Técnicas de Cocultivo , Glucagón/metabolismo , Inmunohistoquímica , Inhibinas/metabolismo , Islotes Pancreáticos , Masculino , Ratas , Células de Sertoli/citología , Porcinos , Factores de Tiempo
6.
Transplant Proc ; 37(1): 477-80, 2005.
Artículo en Inglés | MEDLINE | ID: mdl-15808681

RESUMEN

Xenotransplantation of porcine liver cell types may provide a means of overcoming the shortage of suitable donor tissues to treat hepatic diseases characterized by inherited inborn errors of metabolism or protein production. Here we report the successful isolation, culture, and xenotransplantation of liver cells harvested from 7- to 10-day-old piglets. Liver cells were isolated and cultured immediately after harvesting. Cell viability was excellent (>90%) over the duration of the in vitro studies (3 weeks) and the cultured cells continued to significantly proliferate. These cells also retained their normal secretory and metabolic capabilities as determined by continued release of albumin, factor 8, and indocyanin green (ICG) uptake. After 3 weeks in culture, porcine liver cells were loaded into immunoisolatory macro devices (Theracyte devices) and placed into the intraperitoneal cavity of immunocompetant CD1 mice. Eight weeks later, the devices were retrieved and the cells analyzed for posttransplant determinations of survival and function. Post mortem analysis confirmed that the cell-loaded devices were biocompatible, and were well-tolerated without inducing any notable inflammatory reaction in the tissues immediately surrounding the encapsulated cells. Finally, the encapsulated liver cells remained viable and functional as determined by histologic analyses and ICG uptake/release. The successful harvesting, culturing, and xenotransplantation of functional neonatal pig liver cells support the continued development of this approach for treating a range of currently undertreated or intractable hepatic diseases.


Asunto(s)
Trasplante de Células/métodos , Supervivencia de Injerto/fisiología , Trasplante de Hígado/fisiología , Trasplante Heterólogo/fisiología , Animales , Animales Recién Nacidos , Transporte Biológico , División Celular , Supervivencia Celular , Células Cultivadas , Verde de Indocianina/farmacocinética , Ratones , Albúmina Sérica/metabolismo , Porcinos
7.
Transplant Proc ; 37(1): 487-8, 2005.
Artículo en Inglés | MEDLINE | ID: mdl-15808684

RESUMEN

A Mexican group reported transplantation of cocultured neonatal porcine islets and Sertoli cells resulting in insulin independence in nonimmunosuppressed type 1 diabetes patients. We have transplanted similar islets alone (naked islets) or cocultured islets with sertoli cells (islet/sertoli cells) into an omental site and other locations of seven nondiabetic, nonimmunosuppressed, nonhuman primates. Porcine endogenous retrovirus was not detected in recipient blood 8 weeks after porcine islet grafts, and porcine C-peptide was detected at a very low level in all animals. Histology examination failed to demonstrate obviously recognizable islets, but in the animals transplanted with islet/Sertoli cells at the omentum site, there were some surviving glucagons, pan-cytokeratin, and inhibin stained cells at 8 weeks.


Asunto(s)
Trasplante de Islotes Pancreáticos/inmunología , Células de Sertoli/trasplante , Trasplante Heterólogo , Animales , Animales Recién Nacidos , Supervivencia de Injerto , Macaca , Masculino , Porcinos
8.
Transplant Proc ; 37(1): 506-9, 2005.
Artículo en Inglés | MEDLINE | ID: mdl-15808691

RESUMEN

Interest in porcine circovirus has been stimulated by the recent emergence of postweaning multisystemic wasting syndrome (PMWS) in pigs and the potential use of pig organs for xenotransplantation in humans. Porcine circovirus type 1 (PCV1) is considered to be widespread in pigs but nonpathogenic. Circovirus type 2 (PCV2) is a similar virus but has been differentiated only recently as a separate type. High tissue concentrations of PCV2 are associated with lesions in PMWS cases, but the etiological role of this agent in the disease remains unclear. The presence of PCV1 in New Zealand pigs has been previously reported based on serological data. PMWS has been recently recorded in New Zealand pigs. The epidemiology of PCV2 in New Zealand pigs has not been examined. The purpose of the study was to look for evidence of circoviruses in New Zealand pig herds. Pig circovirus DNA was sought in various tissues using the polymerase chain reaction. Circovirus type 2 was found in New Zealand pig herds, without any evidence that PMWS has ever occurred in these herds. Newborn piglets were shown to have infection, suggesting vertical transmission of the virus.


Asunto(s)
Circovirus/aislamiento & purificación , Porcinos/virología , Envejecimiento , Animales , Infecciones por Circoviridae/epidemiología , Infecciones por Circoviridae/veterinaria , Pulmón/crecimiento & desarrollo , Pulmón/virología , Masculino , Nueva Zelanda , Reacción en Cadena de la Polimerasa , Semen/virología , Enfermedades de los Porcinos/epidemiología , Enfermedades de los Porcinos/virología
9.
J Clin Microbiol ; 42(11): 5353-6, 2004 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-15528741

RESUMEN

This study represents a long-term follow-up of human patients receiving pig islet xenotransplantation. Eighteen patients had been monitored for up to 9 years for potentially xenotic pig viruses: pig endogenous retrovirus, pig cytomegalovirus, pig lymphotropic herpesvirus, and pig circovirus type 2. No evidence of viral infection was found.


Asunto(s)
Trasplante de Islotes Pancreáticos/efectos adversos , Enfermedades de los Porcinos/transmisión , Trasplante Heterólogo/efectos adversos , Virosis/virología , Virus/aislamiento & purificación , Zoonosis/virología , Animales , Humanos , Leucocitos Mononucleares/virología , Porcinos , Enfermedades de los Porcinos/virología , Virosis/transmisión , Virosis/veterinaria , Virus/clasificación
11.
J Med Virol ; 65(3): 525-9, 2001 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11596088

RESUMEN

The objectives of the present study were to establish the presence of hepatitis E virus (HEV) in New Zealand pigs, first by testing for HEV antibody in pig herds throughout New Zealand to measure the herd prevalence, then by attempting to amplify HEV genomic sequences by PCR. Antibody was measured by two independently designed ELISA serology tests. HEV RNA fragments were amplified by RT-PCR of nucleic acid extracted from faeces of 10-12-week-old piglets using primers targeting ORF1, ORF2, and ORF2/3. PCR products were subject to phylogenetic analysis. Antibody to HEV was found throughout New Zealand pig herds as well as in the different age groups within the herds. Twenty herds from 22 tested were positive for HEV antibody (91% herd prevalence). Phylogenetic analysis of the amplified sequences placed this New Zealand strain of HEV closest to the human European strain It-1 (AF 110390) and U.S. swine strain (AF 082843) with 88% and 83% similarity respectively in ORF1. It was concluded that HEV is widely distributed in the New Zealand pig population. Phylogenetic analysis shows that this is a new HEV strain, grouping most closely with the United States/European cluster, which includes HEV strains of both human and swine origin.


Asunto(s)
Virus de la Hepatitis E/genética , Hepatitis E/veterinaria , Enfermedades de los Porcinos/epidemiología , Animales , Heces/virología , Anticuerpos Antihepatitis/sangre , Hepatitis E/epidemiología , Hepatitis E/virología , Virus de la Hepatitis E/clasificación , Virus de la Hepatitis E/inmunología , Virus de la Hepatitis E/aislamiento & purificación , Humanos , Datos de Secuencia Molecular , Nueva Zelanda/epidemiología , Filogenia , ARN Viral/análisis , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Análisis de Secuencia de ADN , Porcinos , Enfermedades de los Porcinos/virología , Zoonosis/virología
12.
Cell Transplant ; 9(6): 895-901, 2000.
Artículo en Inglés | MEDLINE | ID: mdl-11202575

RESUMEN

Transplantation of pig tissues into humans has the potential for cotransferring pig infections. Knowledge of the epidemiology of pig infections transmissible to humans allows the development of risk limitation strategies at the source herd level, but potentially infectious pig endogenous retrovirus (PERV) is ubiquitous in all domestic pigs and therefore is not avoidable. Using a specific and sensitive RT-PCR and nested PCR for PERV nucleic acids with primers, the screening of pigs from New Zealand herds for the presence and expression of the PERV was conducted. The presence of PERV proviral DNA (pol and env region) and viral RNA was demonstrated in all tested pig tissues including pancreas, liver, spleen, brain, heart, and PBMC. Using the same assays it was established that different tissues (liver, spleen, and heart) of nude and nonobese diabetic (NOD) mice previously transplanted with nonencapsulated pig islets were PERV DNA and RNA negative. Alginate polylysine capsules prepared with encapsulated pig islets were tested for possible leakage of viral particles or viral nucleic acids. RNA was extracted from the supernatant of viable encapsulated pig islet cells grown in culture for 2 months. No evidence of PERV RNA or of cellular nucleic acids could be found. Two adult type I diabetic subjects were transplanted with 1 x 10(6) neonatal pig islets encased in alginate capsules into the peritoneal cavity. One patient was immunosuppressed. Both showed evidence of graft function (up to 34% reduction in insulin dose, corresponding increase in serum pig C-peptide) for up to 2 years. DNA and RNA were extracted from PBMC and blood plasma of both patients at 19 months posttransplant. No evidence of PERV proviral DNA or RNA could be detected. Piglet islets contain PERV DNA and RNA, but this does not traverse the capsules used or produce any evidence of infection in nude and nonobese diabetic (NOD) mice or humans.


Asunto(s)
Diabetes Mellitus Tipo 1/terapia , Retrovirus Endógenos/aislamiento & purificación , Trasplante de Islotes Pancreáticos/métodos , Infecciones por Retroviridae/diagnóstico , Zoonosis/virología , Adulto , Animales , Cápsulas , Retrovirus Endógenos/genética , Femenino , Humanos , Masculino , ARN Viral/análisis , Seguridad , Porcinos , Trasplante Heterólogo
13.
Vopr Onkol ; 31(7): 105-9, 1985.
Artículo en Ruso | MEDLINE | ID: mdl-4024554

RESUMEN

The study was concerned with the pathways of protein complexing in tumor growth. The effects of polyamines on blood plasma proteins and, particularly, on ribonuclease were investigated as a possible modifier of protein--protein interactions. In application of an ultrafiltration procedure, in vitro addition of polyamines to blood plasma imitated certain changes in plasma proteins which take place in tumor growth: filtrate showed a rise in the low molecular weight protein fraction, ribonuclease included. Peak concentrations of protein in filtrate were obtained virtually as soon as polyamines were added to incubation medium. The dissociating effect of polyamines was determined on the basis of the polyamine/protein ratio. Protein complexing was shown to be subject to the effects of both polyamines and products of their enzymatic oxidation.


Asunto(s)
Poliaminas/farmacología , Ribonucleasas/sangre , Animales , Proteínas Sanguíneas/metabolismo , Relación Dosis-Respuesta a Droga , Femenino , Técnicas In Vitro , Peso Molecular , Unión Proteica/efectos de los fármacos , Ratas , Espermidina/farmacología , Espermina/farmacología , Factores de Tiempo , Ultrafiltración
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